Parker 398PDSS-6-4 Double End Shutoff Pipe Coupler

Product Description

The PARKER 398PDSS-6-4 is a double end shutoff pipe coupler designed for inline shutoff applications in compressed air, gas, and fluid distribution systems. Constructed from 316 stainless steel, this coupler features a compression inlet connection and a male NPT (MNPT) outlet with a 1/4-18 inch thread size. It is rated for a maximum working pressure of 150 psi, making it suitable for moderate-pressure service lines. Licensed plumbers, pipefitters, and industrial maintenance technicians install this fitting when a positive shutoff is needed at a connection point without removing the line from service.

This coupler is well suited for use in corrosion-resistant fluid handling systems, laboratory gas lines, instrumentation tubing runs, and light industrial plumbing where stainless steel material is required. The compression-by-MNPT end configuration allows direct connection between compression tubing and threaded pipe without additional adapters. The double end shutoff design isolates flow from both sides of the connection, reducing spillage and system downtime during maintenance or line changes.

Key Features

• 316 stainless steel construction provides corrosion resistance in wet, chemical, and marine environments
• Double end shutoff design isolates flow on both sides of the coupling point
• Compression x MNPT end connections for direct tubing-to-threaded-pipe installation
• 1/4-18 inch thread size conforms to standard NPT taper thread specifications
• Rated to 150 psi maximum working pressure
• Compact, single-piece design minimizes installation footprint in tight spaces

Compatibility

Designed as an OEM-style replacement or new-installation fitting for compression tube and threaded pipe systems requiring a 1/4-18 MNPT connection with a double end shutoff function in stainless steel service.

Installation Notes

Installation should be performed by a licensed plumber or qualified pipefitter in accordance with applicable IPC and local mechanical codes. Depressurize and isolate the line completely before removing any existing fitting or installing this coupler. Apply thread sealant or PTFE tape to the MNPT threads per the sealant manufacturer's instructions; do not overtighten, as stainless steel threads can gall. Verify the compression side tubing is cut cleanly and seated fully before tightening the compression nut.